docs/latex/wx/helpinst.tex

   1 \section{\class{wxHelpController}}\label{wxhelpcontroller}
   2
   3 This is a family of classes by which
   4 applications may invoke a help viewer to provide on-line help.
   5
   6 A help controller allows an application to display help, at the contents
   7 or at a particular topic, and shut the help program down on termination.
   8 This avoids proliferation of many instances of the help viewer whenever the
   9 user requests a different topic via the application's menus or buttons.
  10
  11 Typically, an application will create a help controller instance
  12 when it starts, and immediately call {\bf Initialize}\rtfsp
  13 to associate a filename with it. The help viewer will only get run, however,
  14 just before the first call to display something.
  15
  16 Most help controller classes actually derive from wxHelpControllerBase and have
  17 names of the form wxXXXHelpController or wxHelpControllerXXX. An
  18 appropriate class is aliased to the name wxHelpController for each platform, as follows:
  19
  20 \begin{itemize}\itemsep=0pt
  21 \item On Windows, wxWinHelpController is used.
  22 \item On all other platforms, wxHelpControllerHtml is used if wxHTML is
  23 compiled into wxWindows; otherwise wxExtHelpController is used (for invoking an external
  24 browser).
  25 \end{itemize}
  26
  27 The remaining help controller classess need to be named
  28 explicitly by an application that wishes to make use of them.
  29
  30 There are currently the following help controller classes defined:
  31
  32 \begin{itemize}\itemsep=0pt
  33 \item wxWinHelpController, for controlling Windows Help.
  34 \item wxCHMHelpController, for controlling MS HTML Help. To use this, you need to set wxUSE\_MS\_HTML\_HELP
  35 to 0 in setup.h, and link your application with Microsoft's htmlhelp.lib. Currently VC++ only.
  36 \item wxExtHelpController, for controlling external browsers under Unix.
  37 The default browser is Netscape Navigator. The 'help' sample shows its use.
  38 \item wxHelpControllerHtml, using \helpref{wxHTML}{wxhtml} to display help. See {\tt wx/helpwxht.h} for
  39 details of use.
  40 \item \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, a more sophisticated help controller using \helpref{wxHTML}{wxhtml}, in
  41 a similar style to the Microsoft HTML Help viewer and using some of the same files.
  42 Although it has an API compatible with other help controllers, it has more advanced features, so it is
  43 recommended that you use the specific API for this class instead.
  44 \end{itemize}
  45
  46 \wxheading{Derived from}
  47
  48 wxHelpControllerBase\\
  49 \helpref{wxObject}{wxobject}
  50
  51 \wxheading{Include files}
  52
  53 <wx/help.h> (wxWindows chooses the appropriate help controller class)\\
  54 <wx/helpbase.h> (wxHelpControllerBase class)\\
  55 <wx/helpwin.h> (Windows Help controller)\\
  56 <wx/msw/helpchm.h> (MS HTML Help controller)\\
  57 <wx/generic/helpext.h> (external HTML browser controller)\\
  58 <wx/generic/helpwxht.h> (simple wxHTML-based help controller)\\
  59 <wx/html/helpctrl.h> (advanced wxHTML based help controller: wxHtmlHelpController)
  60
  61 \wxheading{See also}
  62
  63 \helpref{wxHtmlHelpController}{wxhtmlhelpcontroller}, \helpref{wxHTML}{wxhtml}
  64
  65 \latexignore{\rtfignore{\wxheading{Members}}}
  66
  67 \membersection{wxHelpController::wxHelpController}
  68
  69 \func{}{wxHelpController}{\void}
  70
  71 Constructs a help instance object, but does not invoke the help viewer.
  72
  73 \membersection{wxHelpController::\destruct{wxHelpController}}
  74
  75 \func{}{\destruct{wxHelpController}}{\void}
  76
  77 Destroys the help instance, closing down the viewer if it is running.
  78
  79 \membersection{wxHelpController::Initialize}\label{wxhelpcontrollerinitialize}
  80
  81 \func{virtual void}{Initialize}{\param{const wxString\& }{file}}
  82
  83 \func{virtual void}{Initialize}{\param{const wxString\& }{file}, \param{int}{ server}}
  84
  85 Initializes the help instance with a help filename, and optionally a server socket
  86 number if using wxHelp (now obsolete). Does not invoke the help viewer.
  87 This must be called directly after the help instance object is created and before
  88 any attempts to communicate with the viewer.
  89
  90 You may omit the file extension and a suitable one will be chosen. For
  91 wxHtmlHelpController, the extensions zip, htb and hhp will be appended while searching for
  92 a suitable file. For WinHelp, the hlp extension is appended. For wxHelpControllerHtml (the
  93 standard HTML help controller), the filename is assumed to be a directory containing
  94 the HTML files.
  95
  96 \membersection{wxHelpController::DisplayBlock}\label{wxhelpcontrollerdisplayblock}
  97
  98 \func{virtual bool}{DisplayBlock}{\param{long}{ blockNo}}
  99
 100 If the help viewer is not running, runs it and displays the file at the given block number.
 101
 102 {\it WinHelp:} Refers to the context number.
 103
 104 {\it MS HTML Help:} Refers to the context number.
 105
 106 {\it External HTML help:} the same as for \helpref{wxHelpController::DisplaySection}{wxhelpcontrollerdisplaysection}.
 107
 108 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 109
 110 This function is for backward compatibility only, and applications should use \helpref{wxHelpController}{wxhelpcontrollerdisplaysection} instead.
 111
 112 \membersection{wxHelpController::DisplayContents}\label{wxhelpcontrollerdisplaycontents}
 113
 114 \func{virtual bool}{DisplayContents}{\void}
 115
 116 If the help viewer is not running, runs it and displays the
 117 contents.
 118
 119 \membersection{wxHelpController::DisplaySection}\label{wxhelpcontrollerdisplaysection}
 120
 121 \func{virtual bool}{DisplaySection}{\param{const wxString\&}{ section}}
 122
 123 If the help viewer is not running, runs it and displays the given section.
 124
 125 The interpretation of {\it section} differs between help viewers. For most viewers,
 126 this call is equivalent to KeywordSearch. For MS HTML Help, external HTML help
 127 and simple wxHTML help, if {\it section} has a .htm
 128 or .html extension, that HTML file will be displayed; otherwise
 129 a keyword search is done.
 130
 131 \func{virtual bool}{DisplaySection}{\param{int}{ sectionNo}}
 132
 133 If the help viewer is not running, runs it and displays the given section.
 134
 135 {\it WinHelp, MS HTML Help:} {\it sectionNo} is a context id.
 136
 137 {\it External HTML help/simple wxHTML help:} wxExtHelpController and wxHelpControllerHtml implement {\it sectionNo} as an id in a map file, which is of the form:
 138
 139 \begin{verbatim}
 140 0  wx.html             ; Index
 141 1  wx34.html#classref  ; Class reference
 142 2  wx204.html          ; Function reference
 143 \end{verbatim}
 144
 145 {\it wxHtmlHelpController:} {\it sectionNo} is an identifier as specified in the {\tt .hhc} file. See \helpref{Help files format}{helpformat}.
 146
 147 See also the help sample for notes on how to specify section numbers for various help file formats.
 148
 149 \membersection{wxHelpController::GetFrameParameters}\label{wxhelpcontrollergetframeparameters}
 150
 151 \func{virtual wxFrame *}{GetFrameParameters}{\param{const wxSize * }{size = NULL}, \param{const wxPoint * }{pos = NULL},
 152  \param{bool *}{newFrameEachTime = NULL}}
 153
 154 This reads the current settings for the help frame in the case of the
 155 wxHelpControllerHtml, setting the frame size, position and
 156 the newFrameEachTime parameters to the last values used. It also
 157 returns the pointer to the last opened help frame. This can be used
 158 for example, to automatically close the help frame on program
 159 shutdown.
 160
 161 wxHtmlHelpController returns the frame,
 162 size and position.
 163
 164 For all other help controllers, this function does nothing
 165 and just returns NULL.
 166
 167 \wxheading{Parameters}
 168
 169 \docparam{viewer}{This defaults to "netscape" for wxExtHelpController.}
 170
 171 \docparam{flags}{This defaults to wxHELP\_NETSCAPE for wxExtHelpController, indicating
 172 that the viewer is a variant of Netscape Navigator.}
 173
 174 \membersection{wxHelpController::KeywordSearch}\label{wxhelpcontrollerkeywordsearch}
 175
 176 \func{virtual bool}{KeywordSearch}{\param{const wxString\& }{keyWord}}
 177
 178 If the help viewer is not running, runs it, and searches for sections matching the given keyword. If one
 179 match is found, the file is displayed at this section.
 180
 181 {\it WinHelp, MS HTML Help:} If more than one match is found,
 182 the first topic is displayed.
 183
 184 {\it External HTML help, simple wxHTML help:} If more than one match is found,
 185 a choice of topics is displayed.
 186
 187 {\it wxHtmlHelpController:} see \helpref{wxHtmlHelpController::KeywordSearch}{wxhtmlhelpcontrollerkeywordsearch}.
 188
 189 \membersection{wxHelpController::LoadFile}\label{wxhelpcontrollerloadfile}
 190
 191 \func{virtual bool}{LoadFile}{\param{const wxString\& }{file = ""}}
 192
 193 If the help viewer is not running, runs it and loads the given file.
 194 If the filename is not supplied or is
 195 empty, the file specified in {\bf Initialize} is used. If the viewer is
 196 already displaying the specified file, it will not be reloaded. This
 197 member function may be used before each display call in case the user
 198 has opened another file.
 199
 200 wxHtmlHelpController ignores this call.
 201
 202 \membersection{wxHelpController::OnQuit}\label{wxhelpcontrolleronquit}
 203
 204 \func{virtual bool}{OnQuit}{\void}
 205
 206 Overridable member called when this application's viewer is quit by the user.
 207
 208 This does not work for all help controllers.
 209
 210 \membersection{wxHelpController::SetFrameParameters}\label{wxhelpcontrollersetframeparameters}
 211
 212 \func{virtual void}{SetFrameParameters}{\param{const wxString \& }{title},
 213  \param{const wxSize \& }{size}, \param{const wxPoint \& }{pos = wxDefaultPosition},
 214  \param{bool }{newFrameEachTime = FALSE}}
 215
 216 For wxHelpControllerHtml, this allows the application to set the
 217 default frame title, size and position for the frame. If the title
 218 contains \%s, this will be replaced with the page title. If the
 219 parameter newFrameEachTime is set, the controller will open a new
 220 help frame each time it is called.
 221
 222 For wxHtmlHelpController, the title is set (again with \%s indicating the
 223 page title) and also the size and position of the frame if the frame is already
 224 open. {\it newFrameEachTime} is ignored.
 225
 226 For all other help controllers this function has no effect.
 227
 228 \membersection{wxHelpController::SetViewer}\label{wxhelpcontrollersetviewer}
 229
 230 \func{virtual void}{SetViewer}{\param{const wxString\& }{viewer}, \param{long}{ flags}}
 231
 232 Sets detailed viewer information. So far this is only relevant to wxExtHelpController.
 233
 234 Some examples of usage:
 235
 236 \begin{verbatim}
 237   m_help.SetViewer("kdehelp");
 238   m_help.SetViewer("gnome-help-browser");
 239   m_help.SetViewer("netscape", wxHELP_NETSCAPE);
 240 \end{verbatim}
 241
 242 \membersection{wxHelpController::Quit}\label{wxhelpcontrollerquit}
 243
 244 \func{virtual bool}{Quit}{\void}
 245
 246 If the viewer is running, quits it by disconnecting.
 247
 248 For Windows Help, the viewer will only close if no other application is using it.
 249